Despite the overwhelming evidence for dark matter from astronomical and cosmological indications at various scales, a clear evidence of a particle which can explain these observations remains absent. XENON1T is a liquid xenon (LXe) detector capable of exploring a large fraction of the available parameter space for weakly interacting massive particles (WIMPs). The experiment aims to detect WIMP-nucleon interactions using a dual phase LXe time-projection-chamber (TPC) with a total target mass of about 2 tons. The sensitivity to spin-independent WIMP-nucleon cross sections is expected to reach 10^{-47} cm^{2} at a WIMP mass of 50 GeV after two ton-years of exposure. XENON1T started its data-taking in the end of 2016, and performed a dark matter search using an exposure of 278.8 days * 1.3 ton = 1.0 ton * year with an electronic-recoil (ER) background rate of ~82 events / (ton * year * keV), the lowest ever achieved in a dark matter search experiment. We found no significant excess over background, and a profile likelihood analysis parameterized in spatial and energy dimensions excludes new parameter space for the WIMP-nucleon spin-independent elastic scatter cross-section for WIMP masses above 6 GeV. In this talk, the details of this dark matter search will be presented. Current status of XENONnT, a fast upgrade experiment of XENON1T, will also be discussed.